Medical marijuana backers’ ASA bid to ease federal controls of the drug was rejected by a U.S. Federal appeals court that ruled the government properly kept the substance in its most-dangerous category.

A three-judge panel of the U.S. Court of Appeals in Washington today upheld the Drug Enforcement Administration’s decision to maintain marijuana as a Schedule I drug under the Controlled Substances Act because there are no adequate scientific studies finding an acceptable medical use.

“The question before the court is not whether marijuana could have some medical benefits,” U.S. Circuit Judge Harry Edwards wrote in the opinion.

Edwards said the court’s review was limited to whether the DEA’s decision declining to reschedule the drug was arbitrary and capricious. He said the court found there was “substantial evidence” to support the agency’s determination that such studies don’t exist.

The case involves an 10-year-old petition from medical marijuana advocates who asked the DEA to reclassify marijuana as a Schedule III, IV or V drug, which would allow for looser regulation. On June 21, 2011, the DEA rejected the request, stating that existing clinical evidence wasn’t adequate to warrant reclassification.

The case is Americans for Safe Access v. Drug Enforcement Administration, 11-1265, U.S. Court of Appeals for the District of Columbia (Washington).